The present invention generally relates to a turbine for flowing fluids, especially a turbine having a vertical power output shaft and several wings projecting vertically out from said power output shaft, which wings are rotatable over an angle of about 90xc2x0 about horizontal shafts, so that the wings, in an active first position, are placed at right angle to the flowing fluid and in a non-active second position are placed horizontally or nearly horizontally on plane with the flowing fluid and with the main plane of the wing, in certain applications preferably closely above the flowing fluid, for instance closely above the water level.
Turbines of the above-mentioned type are known since long, for instance by the patents U.S. Pat. No. 1,484,250, FR 2.481.754, GB 2.196.699 and FR 2.481.754. Said known structures can be used either as water turbines or as wind turbines, or both. They are all formed with a vertical power output shaft and with flat, rectangular wings which can be rotated over an angle of about 90xc2x0 for taking up a maximum water flow power, wave power or wing power during a maximum rotation of the power output shaft over 180xc2x0, generally, however, only over about 120-160xc2x0 for the reason that the active part of the turbine wing is not fold down and obtains a maximum received power until at an angle of 10-30xc2x0 from a zero position, and that the wing, at the end of its active path of movement, receives a successively reduced power, which power in practice is ceased when the power output shaft has rotated about 160-170xc2x0.
Said known turbines are of a simple structure and can be used especially at relative low fluid flows in water or air, but they have for many purposes been considered to give a too low efficiency for being profitable, possibly depending on the relatively short effective rotary path of movement.
Turbines of the said type do not require any height of delivery for its operation but can well be used in flowing watercourses like rivers and water streams, or in tide systems, or in any other water flows, even where the flow speed is relatively low.
The basis of the invention therefore has been the problem of providing a water turbine or wind turbine, especially suited as a water turbine having the same simple structure as previously known turbines but giving a higher efficiency than has previously been possible to reach and in which the turbine wings are formed so that they
both start being seized by the flowing fluid at an earlier stage than has been possible for priorly known turbine wings,
and are fold down to a position at right angle or nearly at right angle to the flowing fluid quicker than has been possible for priorly known turbine wings,
and also maintains the power from the flowing fluid to a greater extent and for a longer period of time than for priorly known flat, rectangular turbine wings.